Peripheral artery disease (PAD) and coronary artery disease (CAD) affect millions of people in the United States alone. PAD and CAD are silent, dangerous diseases that can have catastrophic consequences when left untreated. CAD is the leading cause of death in the United States while PAD is the leading cause of amputation in patients over 50 and is responsible for approximately 160,000 amputations in the United States each year.
Coronary artery disease (CAD) and Peripheral artery disease (PAD) are both caused by the progressive narrowing of the blood vessels most often caused by atherosclerosis, the collection of plaque or a fatty substance along the inner lining of the artery wall. Over time, this substance hardens and thickens, which can cause an occlusion in the artery, completely or partially restricting flow through the artery. Blood circulation to the arms, legs, stomach and kidneys brain and heart may be reduced, increasing the risk for stroke and heart disease.
Interventional treatments for CAD and PAD may include endarterectomy and/or atherectomy. Endarterectomy is surgical removal of plaque from the blocked artery to restore or improve blood flow. Endovascular therapies such as atherectomy are typically minimally invasive techniques that open or widen arteries that have become narrowed or blocked. Often, occlusion-crossing devices can be used to ease the passage of such devices through a blockage.
Minimally invasive techniques can be enhanced through the use of on-board imaging, such as optical coherence tomography (“OCT”) imaging. Images obtained from an atherectomy device, however, can be inaccurate due to the placement of the imaging sensor at a location that is far from the cutter. As a result, it can be difficult to visualize the tissue being cut. Moreover, minimally-invasive techniques can be inefficient, as often many devices are required to perform a single procedure.
Although atherectomy devices having a distal cutting edge that can be covered and exposed by moving a distal tip have been described, the forces necessary to displace the distal tip reliably and repeatedly have proven undesirably large and difficult to operate reliably. Described herein are atherectomy catheter devices, occlusion-crossing devices, and the corresponding systems and methods that may address some of these concerns.